drivers/pinctrl/devicetree.c

   1 /*
   2  * Device tree integration for the pin control subsystem
   3  *
   4  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/device.h>
  20 #include <linux/of.h>
  21 #include <linux/pinctrl/pinctrl.h>
  22 #include <linux/slab.h>
  23
  24 #include "core.h"
  25 #include "devicetree.h"
  26
  27 /**
  28  * struct pinctrl_dt_map - mapping table chunk parsed from device tree
  29  * @node: list node for struct pinctrl's @dt_maps field
  30  * @pctldev: the pin controller that allocated this struct, and will free it
  31  * @maps: the mapping table entries
  32  */
  33 struct pinctrl_dt_map {
  34         struct list_head node;
  35         struct pinctrl_dev *pctldev;
  36         struct pinctrl_map *map;
  37         unsigned num_maps;
  38 };
  39
  40 static void dt_free_map(struct pinctrl_dev *pctldev,
  41                      struct pinctrl_map *map, unsigned num_maps)
  42 {
  43         int i;
  44
  45         for (i = 0; i < num_maps; ++i) {
  46                 kfree_const(map[i].dev_name);
  47                 map[i].dev_name = NULL;
  48         }
  49
  50         if (pctldev) {
  51                 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
  52                 if (ops->dt_free_map)
  53                         ops->dt_free_map(pctldev, map, num_maps);
  54         } else {
  55                 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
  56                 kfree(map);
  57         }
  58 }
  59
  60 void pinctrl_dt_free_maps(struct pinctrl *p)
  61 {
  62         struct pinctrl_dt_map *dt_map, *n1;
  63
  64         list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
  65                 pinctrl_unregister_map(dt_map->map);
  66                 list_del(&dt_map->node);
  67                 dt_free_map(dt_map->pctldev, dt_map->map,
  68                             dt_map->num_maps);
  69                 kfree(dt_map);
  70         }
  71
  72         of_node_put(p->dev->of_node);
  73 }
  74
  75 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
  76                                    struct pinctrl_dev *pctldev,
  77                                    struct pinctrl_map *map, unsigned num_maps)
  78 {
  79         int i;
  80         struct pinctrl_dt_map *dt_map;
  81
  82         /* Initialize common mapping table entry fields */
  83         for (i = 0; i < num_maps; i++) {
  84                 const char *devname;
  85
  86                 devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
  87                 if (!devname)
  88                         goto err_free_map;
  89
  90                 map[i].dev_name = devname;
  91                 map[i].name = statename;
  92                 if (pctldev)
  93                         map[i].ctrl_dev_name = dev_name(pctldev->dev);
  94         }
  95
  96         /* Remember the converted mapping table entries */
  97         dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
  98         if (!dt_map)
  99                 goto err_free_map;
 100
 101         dt_map->pctldev = pctldev;
 102         dt_map->map = map;
 103         dt_map->num_maps = num_maps;
 104         list_add_tail(&dt_map->node, &p->dt_maps);
 105
 106         return pinctrl_register_map(map, num_maps, false);
 107
 108 err_free_map:
 109         dt_free_map(pctldev, map, num_maps);
 110         return -ENOMEM;
 111 }
 112
 113 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 114 {
 115         return get_pinctrl_dev_from_of_node(np);
 116 }
 117
 118 static int dt_to_map_one_config(struct pinctrl *p,
 119                                 struct pinctrl_dev *hog_pctldev,
 120                                 const char *statename,
 121                                 struct device_node *np_config)
 122 {
 123         struct pinctrl_dev *pctldev = NULL;
 124         struct device_node *np_pctldev;
 125         const struct pinctrl_ops *ops;
 126         int ret;
 127         struct pinctrl_map *map;
 128         unsigned num_maps;
 129         bool allow_default = false;
 130
 131         /* Find the pin controller containing np_config */
 132         np_pctldev = of_node_get(np_config);
 133         for (;;) {
 134                 if (!allow_default)
 135                         allow_default = of_property_read_bool(np_pctldev,
 136                                                               "pinctrl-use-default");
 137
 138                 np_pctldev = of_get_next_parent(np_pctldev);
 139                 if (!np_pctldev || of_node_is_root(np_pctldev)) {
 140                         of_node_put(np_pctldev);
 141                         ret = driver_deferred_probe_check_state(p->dev);
 142                         /* keep deferring if modules are enabled unless we've timed out */
 143                         if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret == -ENODEV)
 144                                 ret = -EPROBE_DEFER;
 145
 146                         return ret;
 147                 }
 148                 /* If we're creating a hog we can use the passed pctldev */
 149                 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
 150                         pctldev = hog_pctldev;
 151                         break;
 152                 }
 153                 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
 154                 if (pctldev)
 155                         break;
 156                 /* Do not defer probing of hogs (circular loop) */
 157                 if (np_pctldev == p->dev->of_node) {
 158                         of_node_put(np_pctldev);
 159                         return -ENODEV;
 160                 }
 161         }
 162         of_node_put(np_pctldev);
 163
 164         /*
 165          * Call pinctrl driver to parse device tree node, and
 166          * generate mapping table entries
 167          */
 168         ops = pctldev->desc->pctlops;
 169         if (!ops->dt_node_to_map) {
 170                 dev_err(p->dev, "pctldev %s doesn't support DT\n",
 171                         dev_name(pctldev->dev));
 172                 return -ENODEV;
 173         }
 174         ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
 175         if (ret < 0)
 176                 return ret;
 177
 178         /* Stash the mapping table chunk away for later use */
 179         return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 180 }
 181
 182 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 183 {
 184         struct pinctrl_map *map;
 185
 186         map = kzalloc(sizeof(*map), GFP_KERNEL);
 187         if (!map)
 188                 return -ENOMEM;
 189
 190         /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 191         map->type = PIN_MAP_TYPE_DUMMY_STATE;
 192
 193         return dt_remember_or_free_map(p, statename, NULL, map, 1);
 194 }
 195
 196 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
 197 {
 198         struct device_node *np;
 199         struct property *prop;
 200         int size;
 201
 202         np = pctldev->dev->of_node;
 203         if (!np)
 204                 return false;
 205
 206         prop = of_find_property(np, "pinctrl-0", &size);
 207
 208         return prop ? true : false;
 209 }
 210
 211 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
 212 {
 213         struct device_node *np = p->dev->of_node;
 214         int state, ret;
 215         char *propname;
 216         struct property *prop;
 217         const char *statename;
 218         const __be32 *list;
 219         int size, config;
 220         phandle phandle;
 221         struct device_node *np_config;
 222
 223         /* CONFIG_OF enabled, p->dev not instantiated from DT */
 224         if (!np) {
 225                 if (of_have_populated_dt())
 226                         dev_dbg(p->dev,
 227                                 "no of_node; not parsing pinctrl DT\n");
 228                 return 0;
 229         }
 230
 231         /* We may store pointers to property names within the node */
 232         of_node_get(np);
 233
 234         /* For each defined state ID */
 235         for (state = 0; ; state++) {
 236                 /* Retrieve the pinctrl-* property */
 237                 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 238                 prop = of_find_property(np, propname, &size);
 239                 kfree(propname);
 240                 if (!prop) {
 241                         if (state == 0) {
 242                                 of_node_put(np);
 243                                 return -ENODEV;
 244                         }
 245                         break;
 246                 }
 247                 list = prop->value;
 248                 size /= sizeof(*list);
 249
 250                 /* Determine whether pinctrl-names property names the state */
 251                 ret = of_property_read_string_index(np, "pinctrl-names",
 252                                                     state, &statename);
 253                 /*
 254                  * If not, statename is just the integer state ID. But rather
 255                  * than dynamically allocate it and have to free it later,
 256                  * just point part way into the property name for the string.
 257                  */
 258                 if (ret < 0) {
 259                         /* strlen("pinctrl-") == 8 */
 260                         statename = prop->name + 8;
 261                 }
 262
 263                 /* For every referenced pin configuration node in it */
 264                 for (config = 0; config < size; config++) {
 265                         phandle = be32_to_cpup(list++);
 266
 267                         /* Look up the pin configuration node */
 268                         np_config = of_find_node_by_phandle(phandle);
 269                         if (!np_config) {
 270                                 dev_err(p->dev,
 271                                         "prop %s index %i invalid phandle\n",
 272                                         prop->name, config);
 273                                 ret = -EINVAL;
 274                                 goto err;
 275                         }
 276
 277                         /* Parse the node */
 278                         ret = dt_to_map_one_config(p, pctldev, statename,
 279                                                    np_config);
 280                         of_node_put(np_config);
 281                         if (ret < 0)
 282                                 goto err;
 283                 }
 284
 285                 /* No entries in DT? Generate a dummy state table entry */
 286                 if (!size) {
 287                         ret = dt_remember_dummy_state(p, statename);
 288                         if (ret < 0)
 289                                 goto err;
 290                 }
 291         }
 292
 293         return 0;
 294
 295 err:
 296         pinctrl_dt_free_maps(p);
 297         return ret;
 298 }
 299
 300 /*
 301  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 302  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 303  */
 304 static int pinctrl_find_cells_size(const struct device_node *np)
 305 {
 306         const char *cells_name = "#pinctrl-cells";
 307         int cells_size, error;
 308
 309         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 310         if (error) {
 311                 error = of_property_read_u32(np->parent->parent,
 312                                              cells_name, &cells_size);
 313                 if (error)
 314                         return -ENOENT;
 315         }
 316
 317         return cells_size;
 318 }
 319
 320 /**
 321  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 322  * @np: pointer to device node with the property
 323  * @list_name: property that contains the list
 324  * @list: pointer for the list found
 325  * @cells_size: pointer for the cell size found
 326  * @nr_elements: pointer for the number of elements found
 327  *
 328  * Typically np is a single pinctrl entry containing the list.
 329  */
 330 static int pinctrl_get_list_and_count(const struct device_node *np,
 331                                       const char *list_name,
 332                                       const __be32 **list,
 333                                       int *cells_size,
 334                                       int *nr_elements)
 335 {
 336         int size;
 337
 338         *cells_size = 0;
 339         *nr_elements = 0;
 340
 341         *list = of_get_property(np, list_name, &size);
 342         if (!*list)
 343                 return -ENOENT;
 344
 345         *cells_size = pinctrl_find_cells_size(np);
 346         if (*cells_size < 0)
 347                 return -ENOENT;
 348
 349         /* First element is always the index within the pinctrl device */
 350         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 351
 352         return 0;
 353 }
 354
 355 /**
 356  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 357  * @np: pointer to device node with the property
 358  * @list_name: property that contains the list
 359  *
 360  * Counts the number of elements in a pinctrl array consisting of an index
 361  * within the controller and a number of u32 entries specified for each
 362  * entry. Note that device_node is always for the parent pin controller device.
 363  */
 364 int pinctrl_count_index_with_args(const struct device_node *np,
 365                                   const char *list_name)
 366 {
 367         const __be32 *list;
 368         int size, nr_cells, error;
 369
 370         error = pinctrl_get_list_and_count(np, list_name, &list,
 371                                            &nr_cells, &size);
 372         if (error)
 373                 return error;
 374
 375         return size;
 376 }
 377 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 378
 379 /**
 380  * pinctrl_copy_args - Populates of_phandle_args based on index
 381  * @np: pointer to device node with the property
 382  * @list: pointer to a list with the elements
 383  * @index: entry within the list of elements
 384  * @nr_cells: number of cells in the list
 385  * @nr_elem: number of elements for each entry in the list
 386  * @out_args: returned values
 387  *
 388  * Populates the of_phandle_args based on the index in the list.
 389  */
 390 static int pinctrl_copy_args(const struct device_node *np,
 391                              const __be32 *list,
 392                              int index, int nr_cells, int nr_elem,
 393                              struct of_phandle_args *out_args)
 394 {
 395         int i;
 396
 397         memset(out_args, 0, sizeof(*out_args));
 398         out_args->np = (struct device_node *)np;
 399         out_args->args_count = nr_cells + 1;
 400
 401         if (index >= nr_elem)
 402                 return -EINVAL;
 403
 404         list += index * (nr_cells + 1);
 405
 406         for (i = 0; i < nr_cells + 1; i++)
 407                 out_args->args[i] = be32_to_cpup(list++);
 408
 409         return 0;
 410 }
 411
 412 /**
 413  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 414  * @np: pointer to device node with the property
 415  * @list_name: property that contains the list
 416  * @index: index within the list
 417  * @out_arts: entries in the list pointed by index
 418  *
 419  * Finds the selected element in a pinctrl array consisting of an index
 420  * within the controller and a number of u32 entries specified for each
 421  * entry. Note that device_node is always for the parent pin controller device.
 422  */
 423 int pinctrl_parse_index_with_args(const struct device_node *np,
 424                                   const char *list_name, int index,
 425                                   struct of_phandle_args *out_args)
 426 {
 427         const __be32 *list;
 428         int nr_elem, nr_cells, error;
 429
 430         error = pinctrl_get_list_and_count(np, list_name, &list,
 431                                            &nr_cells, &nr_elem);
 432         if (error || !nr_cells)
 433                 return error;
 434
 435         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 436                                   out_args);
 437         if (error)
 438                 return error;
 439
 440         return 0;
 441 }
 442 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);